| 摘要 |
An oriented heat-sealable polypropylene film comprises a base polypropylene film having on at least one surface at least two layers, the first outer heat sealable layer being a blend of polybutene-1 with polypropylene; the polybutene-1 content lying in the range between 30 and 95% by weight and most preferably in the range between 70 and 80% by weight, and the second layer, lying immediately below the first layer, being a polymer having a preponderance of ethylene and/or butene-1 units, such as low or high density polyethylene or an ethylene/butene copolymer in which ethylene units predominate or polybutene-1 or a butene-1/ethylene copolymer in which butene-1 units predominate. The second layer modifies the sealing properties of the first layer to provide a heat-sealable layer having improved hot tack properties and, in some cases, an improved heat-sealing threshold temperature. |
